Field of the invention
The present invention relates to a method for selecting a resource for v2x operation by a wireless device in a wireless communication system, and to a wireless device performing the method.
Related Art
In International Telecommunication Union Radio communication sector (ITU-R), a standardization task for International Mobile Telecommunication (IMT)-Advanced, that is, the next-generation mobile communication system since the third generation, is in progress. IMT-Advanced sets its goal to support Internet Protocol (IP)-based multimedia services at a data transfer rate of 1 Gbps in the stop and slow-speed moving state and of 100 Mbps in the fast-speed moving state.
For example, 3rd Generation Partnership Project (3GPP) is a system standard to satisfy the requirements of IMT-Advanced and is preparing for LTE-Advanced improved from Long Term Evolution (LTE) based on Orthogonal Frequency Division Multiple Access (OFDMA)/Single Carrier-Frequency Division Multiple Access (SC-FDMA) transmission schemes. LTE-Advanced is one of strong candidates for IMT-Advanced.
There is a growing interest in a Device-to-Device (D2D ) technology in which devices perform direct communication. In particular, D2D has been in the spotlight as a communication technology for a public safety network. A commercial communication network is rapidly changing to LTE, but the current public safety network is basically based on the 2G technology in terms of a collision problem with existing communication standards and a cost. Such a technology gap and a need for improved services are leading to efforts to improve the public safety network.
The public safety network has higher service requirements (reliability and security) than the commercial communication network. In particular, if coverage of cellular communication is not affected or available, the public safety network also requires direct communication between devices, that is, D2D operation.
D2D operation may have various advantages in that it is communication between devices in proximity For example, D2D UE has a high transfer rate and a low delay and may perform data communication. Furthermore, in D2D operation, traffic concentrated on a base station can be distributed. If D2D UE plays the role of a relay, it may also play the role of extending coverage of a base station.
Meanwhile, the D2D operation may also be applied to vehicle-to-everything (V2X) communication. The V2X communication refers to communication technology with vehicles via all interfaces. Embodiments of V2X include, for example, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-person (V2P) communications, and the like.
When a first wireless device performs V2X communication with a second wireless device, and if the second wireless device also transmits a signal using the same or partially overlapped resource as that used by the first wireless device, this may cause mutual interference, and, thus, reliable V2X communication will be difficult to perform. For example, resources for V2X communication are supplied in the form of a resource pool. In fact, resources used to perform V2X communication may be selected from the resource pool by wireless devices. In this case, because different wireless devices arbitrarily choose their own resources from the same resource pool, the same or partially overlapping resources from each other may be selected by the different wireless devices.
Thus, a method for efficiently selecting resources for V2X operation and a wireless device performing the above method are needed.